1. Why do you learn square roots?
Square roots are used to find the side length of a square when you know the area of the square.
Square Root of a Number
If b2 = a, then b is a square root of a.
Example: 32 = 9 and (-3)2 = 9, so 3 and -3 are square roots of 9.
All positive real numbers have two square roots, a positive square root (also called principal square root) and a negative square root.

2. Perfect Squares
The square of an integer is called a perfect square.
Example: 42 = 16, therefore 16 is a perfect square.
A perfect square is a number whose positive square root is a whole number.
Example:
= 4

3. Perfect Squares 64
225 1 81 4
400
100 9
121
625 16
144 25
169 36
196 49

4. Perfect Squares = 1 = 8 = 15 = 2 = 9 = 20 = 10 = 3 = 30 = 11 = 4 = 12
= 5
= 13
= 6
= 14
= 7

5. = 10
= 11
= 2
= 1
= 15
= 8
= 9
= 20
= 3
= 4
= 30
= 12
= 13
= 5
= 14
= 6
= 7